Friction gearing with an adjustable gearing ratio



Oct- 9 1951 LAMBERTUS-WILLEM SCHMIDT 2,570,493

FRICTION GEARING WITH AN ADJUSTABLE GEARING RATIO Filed April 4, 1946 2Sheets-Sheet l Lambenus l W/em Schm/df By his of/orneys FRICTION GEARINGWITH AN ADJUSTABLE GEARING RATIO LAMBERTUS-WILLEM SCHMlDT 2 Sheets-Sheet2 Filed April 4, 1946 3/ WIIIIIIIIIIIIIIIII //2 van /0/ Camber/us l l///em 5c/7m/d/ By Ms Attorneys Patented Oct. 9, 1951 FRICTION GEARINGWITH AN ADJUSTABLE GEARING RATIO Ilambertus-Willem Schmidt, The Hague,Netherlands Application April 4, 1946, Serial No. 659,609 In theNetherlands January 4, 1946 The invention relates to a friction-gearingfor an adjustable gearing-ratio with a friction-cone and a friction-ringsurrounding samewith which one of these parts is coupled with thedriving axle whereas the other part is coupled with the driven axle. Bymutually adjusting the friction-cone and the friction-ring thegearingratio will be altered.

If, with such a friction-gearing a friction-cone and a friction-ring areused, always touching each other according to a straight line, the

mutual adjustment of these parts can be reached in a simple way but thedrawback will be experienced that a clean evolving of thefriction-members over each other will be achieved at the utmost with onedefinite gearing-ratio, whereas with the greater part of the othergearing-ratio there is a strong deviation in the clean evolving of thesemembers, causing a great heat development, which means loss of energyand strong wear of the friction members, whereas chance of slippingwillbe increased. e

The object of the invention is. to provide a friction-gearing with whichthe clean evolving of the friction members over each other will beclosely approximated in every adjustment.

To this end according to the invention the cooperating friction planesof the friction members are correspondingly circle-arc shaped in axialcross section, these members being mutually turnable about an axis whichperpendicularly crosses the axes of rotation of the friction planes andwhich contains the centre of the curve of contact between the frictionplanes. Therewith the friction-gearing according to the invention may beprovided with two pairs of friction planes cooperating in pairs; whichpairs being arranged one after another and of which the adjacentfriction planes of the one endof the other. pair are mutually coupledand are rotatably supported in a holder which is turnable about an axis,which perpendicularly crosses the axes of rotation of all frictionplanes and which contains the centres of both curves of contact betweenthe friction planes.

Referring to the drawing the invention will now be elucidated by someembodiments.

Fig. 1 is a diagrammatic illustration of the principle according to theinvention;

Fig. 2 is a plan view, partly in horizontal cross section of the firstembodiment;

Figs. 3 and 4 are, respectively, a side view partly in section and aplan view of a second embodiment in which the required pressing forcebetween the cooperating friction surfaces is ob- 4 Claims. (Cl. 74- 193)2 tained by means of a spring, Fig. 4 also showing the casing adapted toswing about an axis underneath the casing and parallel to the axis ofrotation of this friction'member;

Fig. 5 is a vertical section of the third embodiment.

As appears from Fig. 1 the friction-gearing according to the inventionprincipally consists of a friction-cone I arranged on a driving shaft 2and of a friction-ring 3 surrounding the cone I and. mounted on a drivenshaft 4. The axial section of the friction-plane of the cone I and ofthe ring 3 consists of a similar circle-arc with a centre 5. This centre5 coincides with the axis of an axle 6 about which axle the cone I andthe ring 3 can turn mutually to alter the gearing-ratio. In this way itis obtained that in spite of the large width of the friction plane 3,which is favourable for the transmission of a large power and forkeeping low the specific surface pressure, as yet the condition a:b=c:dwhich applies to clean evolving of the friction planes over each otherin each possible mutual position of the friction planes will always beclosely approximated.

The principle according to Fig. 1 is applied to the gearing shown inFig. 2. Therewith' a friction-cone 8 is mounted on the rotor-shaft of anelectric motor 1. The motor I with cone 8 are turnable about an axle 9.The friction-ring II] which is to be driven is fitted in a bushing I3which is rotatably arranged in a fixed housing II, the roller bearingsI2 between the bushing and the housing being axially shiftable withinthehousing II. At the end of the bushing Hi there are two sloping rollerpaths I4 supporting two rolls l5 arranged at both sides of the axle [6.The axle I6 is rotatably supportedin the housing II and in the bushingI3. A spring I! pushes the friction-ring I8 against the frictioncone 8by which, during rotation of the cone 8,

the ring I8 with its bushing I3 has the tendency to rotate with it. As aresult the bushing I3 will be displaced by the cooperation of therollerpaths I4 and the rolls l5 by which the ring I8 will be pressed more andmore firmly against the cone 8 until the latter finally will drive thering I8 and the axle I6 without slipping.

' For altering the gearing-ratio it will be sufficient to turn theelectric motor 1 about the axle of rotation 9 till it reaches thedesired position.

With the second embodiment according to Figs. 3 and 4 the friction-ringI8 which is to be driven, is rotatably supported in a housing I9 whichis 4, the driving axle 32 under influence of the spring 42 will takealong the friction-ring 38 with its holder 40, the friction-ring 39 withits holder 4| remaining in rest for the time being. By this the holders40 and 4| will be screwed out of each other a little causing an increaseof the contact-pressure between the cooperating friction-planes. Thismoving from each other of the holder is continued till thecontact-pressures between the friction-planes 36 and 38 on J one handand the planes 31 and 39 on the other hand have increased to such anextent that no the spring 2| is supported and the ring I8 is pressedagainst the cone 22 still firmer until the cone 22 takes the ring ISwith it without slipping and the axle 23 is thus rotated.

By the rotation of the electric inotor about the axle 2'! the mutualposition of friction-cone and friction-ring and by this thegearing-ratio are altered.

With the embodiments described when altering the gearing-ratio of thegear, the mutual position of driving and driven axle must be altered. Ifit is desirable to maintain unaltered the mutual position of driving anddriven axle it is preferable to use a construction according to theembodiment shown in Fig. 5. In this embodiment the driving axle 32 andthe driven axle 33 are rotatably supported in the housing 31 by means ofroller bearings 34 and 35, but in a mutually pre-fixed position.

Within the housing 3| the axles 32, 33 are each provided with a frictioncone 35, 3! respectively.

, There is a friction ring 38 cooperating with the cone 35 and afriction ring 39 cooperating with the cone 3?.

The friction ring 38 is fitted in a holder 40 and the ring 39 in aholder 4|. The two holders are coaxial and overlap. The holder 40 isprovided internally with a coarse screw thread, coupling with acorresponding screw thread on the outside of the holder 4|. In this waythe holders have a limited axial component of movement with relation toeach other. There is a compression spring 42 fitted in a recess inholder 4| and interposed between the two holders. This spring tends topush the two rings 38, 39 apart and thus keep each friction ring pressedinto engagement with its complementary friction cone. 7

The holder 45 is mounted in a supporting bushing 43 and while the holdercan shift longitudinally it cannot rotate with relation to the bushing.However, the bushing is rotatably sup-' ported in a-holder or casing 45by means of roller bearings '44. This casing is provided with anadjusting lever 46 reaching through a slot '47 in the housing 3|. Thecasing is turnable or swingable about its axle 43 which is mounted inthe'sid'e walls of the housing 3|. The center line of this axle isdirected at angles to the plane which contains the axes of rotation ofall the friction members 33, 31, 38,39. In addition,

the center line of 'theaxle also coincides with spring 42 pushes bothfriction-rings 3B and 39 c from each other and against thefriction-cones 36, resp. 31. The cone 35 which is mounted on slippingwill appear any more between the cothe parts supported thereby isadjusted about the axle 43 and the gearing-ratio of the gearing isaltered.

I claim: H V

1. A friction gearing with anadjustable gearing radio having two pairsof friction members, each pair comprising a friction cone with .aconcave friction surf-ace and a friction ring in engagement therewith,the contacting friction surfaces being correspondingly shaped in axialcross-section in the anc of a circle, in combination with a casing inwhich coaxially coupled holders for the friction rings are rotatablysupported, said casing being swingable about an axis, the center line ofwhich is directed at right angles to the plane which contains the axesof rotation of all the friction members, said center line coincidingwith the centers of the curva tures of the lines of contact of thecontacting friction surfaces, said holders for the friction rings beingmovable axially with a limited component of movement with relation toeach other, and a compressionspring interposed between said holders tokeep each friction ring pressed into engagement with its complementaryfriction cone.

2. A friction gearing according to claim 1 in which the intercoupli'n'gof the friction ring holder's comprises interengaged inclined surfacesfixed to said holders.

3. A friction gearing according to claim 2 in which the inclinedsurfaces are helical.

4. A friction gearing according to claim 3 in which the inclinedsurfaces consist of inclined helical surfaces mounted on one of saidholders and of cooperating rollers on the otherholder.

LAMBERTUS-WILLEM SCHMIDT.

REFERENCES CITED The following references are ofrecord in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 457,100 Yates Aug. 4, 18911,050,351 Dean I Jan. 14, 1913 1,181,218 Fullerton May 2,1916 1,544,6971 'Stoeckicht July 7, 1925 2,142,780 Kohl Jan. 3, 1939 FCSREIGN PATENTSNumber Country I Date V 3,304 Great Britain ,May 7,1903 211,996Switzerland Jan. 16, 1941

